The working principle of high performance quartz accelerometer
High performance accelerometer is one of the devices for measuring linear acceleration of objects based on Newton’s second law in inertial system. In the acceleration process of the sensor, the acceleration value is calculated by measuring the inertial force of the mass block, and the linear velocity can be obtained by integrating the time with the known initial velocity, and the linear displacement can be calculated by integrating again. The product structure of the accelerometer is to use the sensitive structure to convert the change of linear acceleration into the change of capacitance, and finally read the change of capacitance value through the application-specific integrated circuit, so as to measure the acceleration value of the movement of the object.
Classification of high performance quartz accelerometers
According to performance, quartz acceleration can be scored into consumer level, tactical level and navigation level. ER-QA-03A, as one of the representative products of high-performance quartz accelerometers, has a zero bias stability of 10-50μg, a measurement range of ±50g and a scale factor repeatability of 15-50 PPM. Whether it is from zero bias stability or measurement range, it has high applicability. In addition, the performance indicators of this product are high measurement accuracy, good repeatability, high reliability, small size, light weight, wide voltage power supply, low power consumption. High-performance quartz accelerometers can measure the well trajectory and the actual position of the bit in the field of resource exploration drilling and production, so as to ensure that the well depth reaches the predetermined position. In particular, the oil exploration industry has higher requirements for slope and orientation measurement, and ER-QA-03A can also accurately complete the data measurement task.
Structure of high performance quartz accelerometer
The quartz accelerometer is composed of yoke iron and soft magnetic material with low temperature coefficient and good magnetic permeability, and the magnetic steel is processed by grinding machine with permanent magnet material with good magnetic permeability. The material of the flexible sheet is quartz glass with excellent temperature performance, and the shape is made of ultrasonic processing. The processing of the flexible element is generally carried out by chemical corrosion method, and the whole flexible sheet can also be processed by reactive ion etching process.
Application of high performance quartz accelerometer
With the development of science and technology, inertial navigation system has increasingly higher requirements for accelerometer performance, requiring accelerometers with small size, low cost, high precision and high reliability. Quartz accelerometers obviously meet these requirements, so it has a broad application prospect in the field of inertial navigation. In the field of aerospace, quartz flexible accelerometers can be used in aerospace high-precision navigation systems, attitude control and flight attitude control. With the improvement of the performance requirements of different motion systems, accelerometer is an important tool to study the flutter and fatigue life of various aircraft in flight tests. Therefore, the linear accelerometer can be installed in the moving object to directly measure its acceleration, and then get the speed and position, the measurement accuracy is high, the dynamic performance is good, far better than the air speedometer, odometer.
In safety applications, the fast response of accelerometers is very important. Acceleration sensors can be used in safety performance such as automotive airbags and anti-traction control systems. When the airbag should be deployed needs to be determined quickly, so the accelerometer must respond in a split second. The response time of the device can be reduced by using a sensor design that can quickly reach a steady state rather than a vibration. Among them, piezoresistive acceleration sensors are developing the fastest due to their wide application in the automotive industry.
In the mechanical field, it can be used for vibration analysis and mechanical fault diagnosis; In earthquake research, it can be used for map construction and earthquake prediction. With the emphasis on safety and predictability, the market demand for quartz flexible accelerometers will further increase.
